A single clinic on Florida's west coast has seen six cases in the past month of hemorrhagic diarrhea and vomiting accompanied by high fevers in dogs predominantly from a poor section of Sarasota County, veterinarians from the clinic said this week.

Dr. Steve Koch, owner of Tuttle Animal Medical Clinic, and his associate, Dr. Eva Ojolick-Ryan, told VIN News Service that five of the six dogs died within 24 hours of being at the hospital. Most had been sick for only one or two days before being seen.

The cause of the outbreak is unknown.

Apart from the fact that all but two of the dogs had lived in a low-income area, Koch said they had little in common. “They varied anywhere from (about) age 8 months to 6 years,” he recounted. “Some had had every vaccine out there, including 4-way lepto; some had had no vaccines at all. One of the dogs, (the owner) had only owned it for a day, so he had no history. It runs the gamut.”

Four of the six dogs were Pit Bulls, Ojolick-Ryan said. The others were a Greyhound and an American Eskimo.

Koch said one animal from outside the area was a well-cared-for Pit Bull that was up-to-date on his vaccinations. It had moved from Daytona Beach and was in Sarasota only four days when it became ill.

Koch said the sick dogs had extremely high temperatures, in the neighborhood of 107 F, and very bloody diarrhea and vomitus: “I mean, it’s pure blood,” he said.

The dogs had low white-blood cell counts, soaring serum creatinine values and acute renal failure and destruction, Ojolick-Ryan said. “Urine also turned from yellow at onset to brown near death,” she said.

Most of the dogs’ owners were of limited means and unable to pay for diagnostic lab work, the veterinarians said. Koch said his clinic picked up the bill for tests for parvovirus and leptospirosis on some of the patients. The results were negative.

“The clinic has picked up the cost of a lot of the blood work and treating, too, to try and save these dogs,” Ojolick-Ryan said. "So diagnostics have been limited, as well as post studies.”

The veterinarians discussed whether rawhide chews might be a factor, but case notes provided by Ojolick-Ryan show that only three of the six dogs were given rawhide treats. “We were grasping at straws,” Koch said.

The cases began showing up on June 22 — two back-to-back that day. The most recent patient came to the clinic on July 28.

In trying to solve the mystery, the clinic contacted a variety of experts, among them Dr. Cynda Crawford, an immunology and infectious diseases expert at the University of Florida College of Veterinary Medicine. Crawford agreed to look into the matter, and Ojolick-Ryan sent her some data.

However, Crawford told VIN News Service by e-mail last Wednesday that she had nothing to report. “There is very little case material to work with, so am struggling with meaningful diagnostic approaches,” she wrote. “...Everything is basically speculation at this point.”

Dr. Bill Jeter, a veterinarian and bureau chief of contagious and infectious diseases in Florida’s Division of Animal Industry, said his department is monitoring the situation.

He noted that there was some discussion among his colleagues that the outbreak could be caused by infections of a virulent strain of E. coli. In humans, exposure to E. coli 0517:H7 can lead to hemolytic-uremic syndrome (HUS), the onset of which may include bloody vomiting and diarrhea. HUS occurs when toxins produced by E. coli destroy red blood cells.

Among people infected by E. coli, HUS is seen mostly in children, the elderly and adults with weak immune systems. It is rare in dogs, but not unheard of.

Ojolick-Ryan, continuing to work on the cases while on vacation in Canada, said by e-mail Friday that she’s following up on the HUS angle by sending fecal samples to Dr. Alice Agasan, chief of the bureau of diagnostic laboratories in the state Department of Agriculture.

She said she is also sending tissue samples to Crawford. “I only have samples from one case so far,” Ojolick-Ryan said. “If — heaven forbid — we get another case, more samples will be taken.”

Jeter said that if the diagnosis turns out to be HUS, it would be odd to see an outbreak confined to one clinic. “I haven’t heard of anybody else reporting it,” he said. “I’m sure if it was (being found elsewhere), we’d be hearing about it.”

Ojolick-Ryan said she heard of one other case, in south Charlotte County, involving a Greyhound with similar symptoms. But she was unable to confirm whether the case could be considered part of the same outbreak.

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